1. Field of the Invention
The present invention relates generally to a driver for screws or other fasteners, and more particularly to a hand-held driver which has a plastic shaft for receiving driving bits. The shaft includes a retaining ring adjacent to the bit receiving end. The handle includes bit holding slots having integral retention means for the bits.
2. Description of the Related Art
Devices for driving screws and the like are well known in the art, and have changed very little throughout the years. The typical driver, i.e., a screwdriver or nut driver, includes a handle, which is often made of plastic, and a metal shaft which extends from the handle. The shaft has a relatively small diameter so that the driver may be used in areas with limited access. The end of the shaft distal from the handle includes a hexagonal recess for receiving conventional driving bits. These types of bits are hexagonal on one end for being received by the driver, and include a driving end for installation and removal of the fastener to which the driving end corresponds. The driving bit may be, for example, a slotted, phillips or torx screwdriver, or a nut-driver bit.
Hand-held drivers of this type are shown, for example, in U.S. Pat. Nos. 4,227,430 and 4,924,733. The driving end of these types of drivers is subject to high torque forces. Thus, none of the drivers of this type employ a plastic or other nonmetallic shaft, since the torque at the driving end would likely cause premature failure of the shaft which would result in the bit stripping or cracking the shaft. This necessitates the use of a plastic handle with a metallic shaft and the increased cost of manufacture associated therewith.
U.S. Pat. No. 5,263,389 relates to a marine propeller wrench constructed of a plastic material impregnated with glass fibers. An annular reinforcing ring provides additional hoop strength to the socket portion. This device is constructed of relatively expensive materials to provide the necessary strength for a wrench, and as such is not practical for a mass-produced driver.
Drivers having handles for storing bits are also well known in the art. Such devices are shown, for example, in U.S. Pat. Nos. 3,683,984; 4,227,430; 4,434,828; 4,716,795; 4,924,733; 5,325,745; and 5,335,409. In these types of drivers, the handle of the driver typically includes several slots in which the driving bits are inserted. Retention means is provided for holding the driving bits within the slots. For example, in U.S. Pat. No. 4,434,828, sleeves of resilient material are press-fit into openings in the handle. U.S. Pat. No. 5,325,745 employs leaf springs which are used to hold the bits in the slots. U.S. Pat. No. 3,683,984 employs another type of spring to hold the bits in the slots. In U.S. Pat. No. 4,227,430, a portion of the handle may be rotated to expose the bits, which are stored within the handle. Finally, in U.S. Pat. No. 4,924,733, another type of spring mechanism is utilized.
In those patents in which a spring is utilized to hold the bit within each slot, the spring is a separate element from the handle. This increases the cost and complexity of manufacturing these drivers.